Investigating distant effects of the Moesian promontory: brittle tectonics along the western boundary of the Getic unit (East Serbia)

Abstract

In this study, we report evidence for brittle deformation in a part of the Carpatho–Balkan orogen, which is explained in terms of effects of the rigid Moesian promontory of the European plate on fault kinematics in East Serbia. We focus on the westernmost part of the Getic Unit of the East Serbian Carpatho–Balkanides, i.e. the Gornjak–Ravanica Unit, located between two main thrusts that were repeatedly activated from Early Cretaceous to recent times. We combine a new data set on fault kinematics and tectonic paleostress tensors, with literature data about neotectonic and recent fault activity, in order to reconstruct brittle tectonic events that were active in this area since Oligocene times. Two brittle tectonic phases were distinguished. The older phase was most probably active from the Oligocene to the end of the middle Miocene, and was characterized by the activation of faults that accommodated a complex sequence of clockwise rotations of the Dacia mega-unit around the rigid Moesian promontory. The younger deformational phase most likely started in the late Miocene and is probably still active in recent time. It is characterized by strike-slip tectonics, resulting from the far-field stress generated by the collision of the Adriatic microplate, the Moesian promontory and the tectonic units in between. This stress field is shown to be highly heterogeneous even in the relatively small research area; local areas of transtension and transpression have also been very important in controlling the fault kinematics in the western part of the Getic Unit.